Search

The concept of forest productivity is biologically complex. In forest masses, it is indirectly estimated via dominant height growth models and site indices. The aim of this study was to develop a dominant height model for Gmelina arborea using data from 129 monitoring plots. 9 dynamic equations were generated from the Hossfeld and Bertalanffy-Richards theoretical models, which were individually fitted and cross-validated. Among the evaluated models, the Bertalanffy-Richards model (parameter c) stood out. This model showed a logical biological trend, with polymorphic curves and a unique asymptote. The selected model is an important tool for the management of G. arborea forest plantations in areas with site characteristics similar to those of this study. [ABSTRACT FROM AUTHOR]

This article evaluated the relationship between litter production and decomposition in a High-Andean forest and several variables, including rainfall, soil, and structural and floristic characteristics. Litter traps, litter-bags, and rain gauges were installed, and various variables were recorded. The total fine litter production was 4780 kg.ha-1.year-1, with leaves as the most representative fraction (60.4%), while decomposition was between 25 and 30% for 195 days of measurement. Significant correlations were found between fine litter production and incident precipitation (0.60), between height (-0.98) and aboveground biomass (0.97), and between decomposition and moisture (0.75). The results suggest that changes in the forest structure or weather conditions could affect the regulation of ecosystem and biogeochemical functions, highlighting the importance of conserving High-Andean forests, which are threatened by deforestation and climate change. [ABSTRACT FROM AUTHOR]

Non-timber forest products (NTFP), such as wild berries, are of great importance for rural communities and vulnerable social groups due to the economic income they might generate and their role in these people's nutrition. To optimize forest plants productivity is necessary to study their ecological needs, such as light availability. Calafate (Berberis microphylla) fruits are NTFP of interest. However, there is little information about the relation between their productivity and light availability. In this study, the potential of a native mixed shrubland as supplier of calafate fruits and its relation with light availability was analyzed. To achieve this, the presence and number of fruits in calafate plants naturally established in a native shrubland in El Foyel, Río Negro, and exposed to different light intensities were evaluated. An estimation of the productivity of the shrubland sampled was also made for different levels of light availability. Generalized linear models were used to analyze the data. It was found that greater canopy openness corresponded to a higher probability of fruiting and to a greater number of fruits per plant. In addition, a positive relationship was found between plant height and number of fruits. It was estimated that the highest fruit production would be found in a 100% canopy openness scenario, in which case, ~54.87 kg/ha would be obtained. It was concluded that light availability is an essential factor for calafate fruiting. Moreover, considering that the average canopy openness of the sampled shrubland was 22.2%, it is considered that an appropriate environmental management is necessary to optimize the use of this species in a sustainable and economically convenient way. [ABSTRACT FROM AUTHOR]

The article titled "Public Forest Ownership and Energy Use of Forest Biomass in Castilla y León" analyzes the importance of forest biomass District Heating & Cooling systems in the energy transition. The author examines the legal framework regulating forests in Castilla y León and the barriers that hinder biomass extraction, especially in forests classified as public utility. The different categories of public and private forests are also studied, as well as the regulation of timber and woody uses in state-owned forests. The article offers practical solutions for the bidding of uses in forests classified as public utility, with the aim of allocating them to energy production in forest biomass power plants. This work is a reference for professionals in the forestry sector and can facilitate the extraction and use of timber and woody resources in Castilla y León. [Extracted from the article]

In any production process, if it is to be sustainable, the available natural, material and human resources must be used appropriately. The logistics of usage determines the effectiveness of the process and the achievement of the desired results. The objective of this study is to analyze the management of forestry production in terms of the productive chain, since its beginning in plantations or natural forests, to the marketing and business processes of forestry companies, going through different logistically structured and planned processes, related to the efficiency of sustainable forest management. In order to do so, theoretical methods of bibliographic search of the subject were used, supported by the productive chain model of a company in terms of value and results of research carried out. An alternative for management is presented, which can be applied in any forestry company. [ABSTRACT FROM AUTHOR]

The general objective of this study was to provide information regarding the productivity and site quality of Palo Santo forests in their Argentinean distribution area in order to establish guidelines for sustainable management and use. We used data taken from 482 plots as part of national, regional and local forest inventories in northern Argentina, carried out in native forests within aboriginal and peasant community tenures and management plans. Basal area, stem volume and dominant height of Palo Santo trees were used to determine site quality class. This was correlated to forest structure by using a classification mosaic from Landsat satellite images. A sustainable cutting cycle duration and harvest intensity for Palo Santo forests were calculated according to their site quality. The results suggest that the current stocks of Palo Santo are sufficient to continue with its sustainable use without compromising its longterm availability. This information is useful for decision makers and defines the potential of the species to provide resources to regional economies and provincial productive development. [ABSTRACT FROM AUTHOR]

Site index models allow for the characterization of forest site productivity and the development of management strategies to achieve objectives of production and conservation of forest resources. The goal of this study was to fit and validate growth models of dominant height and site index for Pinus oaxacana Mirov. The database was derived from 4 inventories in 44 permanent plots and 58 temporary plots, established in even-aged stands located in Ixtlán de Juárez, Oaxaca, Mexico. The data were randomly partitioned into subsets of 50 %, 60 %, 70 %, and 80 % for the model adjustments and the remaining data for each subset were used for cross-validation. The models fitted were Korf, Hossfeld IV and Chapman-Richards, in their expressions ADA (algebraic difference approach) and GADA (generalized algebraic difference approach), using the nested iterative method under the non-linear least squares technique. The models that presented the best statistics for fit and validation were: in ADA, anarmorphic Korf b0 (70 %) and polymorphic Korf b1 (80 %); in GADA, Chapman-Richards (70 %) and Korf (80 %). The Chapman-Richards GADA model presented the most suitable graphical behavior and was selected to classify the forest site productivity. The dominant height and site index model applied to quantify the productive potential of P. oaxacana stands constitutes a valuable tool for the sustainable management of this species in the forests of Oaxaca, Mexico. [ABSTRACT FROM AUTHOR]

Gonopterodendron sarmientoi is a native tree species from Chaco region forest that grows in mixed forest or in pure dense forests (palosantales). Due to habitat destruction and high exploitation, G. sarmientoi is threatened; hence, baseline information about the forests where the species grows is needed to guide future management and conservation programs. The objective of this article is to characterize the environment, genetic diversity and morphology of G. sarmientoi's palosantales (n=10), in relation to the species' mixed forests (n=14). For that, along the whole range of the species distribution, we compared the palosantales and mixed forests regarding their composition of plant species and site attributes (soil type and vegetation index), genetic diversity obtained with neutral markers, and leaf and tree morphological traits. The palosantales were characterized by having fewer companion species forests (mean 8; min. 1; max. 14), predominantly with shrub species, in relation to mixed forests (mean 10; min. 8; max. 13). The soils of the palosantales showed high content of clay and low levels of organic carbon and sand. The lowest nutrients sampled sites were palosantales located in the center-west of the species range, in the triple border Argentina-Bolivia-Paraguay, and in the palosantales on Bermejo river paleochannels (Argentina). The vegetation index confirmed the low productivity of palosantales forests (NDVI palosantales 0.38; NDVI mixed forests 0.51). The palosantales were similar in genetic diversity with respect to mixed forest (nucleotide diversity 0.00103 vs 0.00120; Shannon index 0.89 vs 1.02, respectively). Morphologically, G. sarmientoi trees in the palosantales were shorter and shrubbier than the mixed forest trees. The forests of G. sarmientoi require focused research that considers the singularities of each type of forest, allowing conservation of the species and the derived ecosystem services. [ABSTRACT FROM AUTHOR]

Copyright of Recursos Rurais is the property of Universidad de Santiago de Compostela, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Económicas CUC is the property of Corporacion Universidad de la Costa, CUC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ecological footprint is an important tool to establish both the impact of human activities on the ecosystem and the corrective measures to mitigate these impacts. It transforms all consumption of material and energy into productive land (crops, pastures, forests, sea, built soil or CO2 absorption) giving us a clear and precise idea of the impact of our activities on the ecosystem. It is the "final" indicator because it transforms any type of consumption unit (tons, kilowatts, liters, etc.), as well as the produced wastes, into a single totally significant number. In this paper the Corporate Ecological Footprint was determined, a global and synthetic indicator that allows progress in the evaluation of the sustainability of the Molinera Frank País García Company in the municipality of Santiago de Cuba. For the calculation of the corporate ecological footprint, the proposed methodology in the document: "Methodological Guide for the Calculation of the Corporate Ecological Footprint" Doménech was used, with adaptations introduced in order to bring it to the field of the present study. The result obtained from the corporate ecological footprint was 0.02 ha / t, broken down into energy sub-tracks 0,011 032 ha / t, inputs 0,002 262 84 ha / t, built area 1,013 99e-06 ha / t, indirect costs 0,000 400536 ha/t waste emissions and discharges with a value of 0,014 952 7 ha / t, which represented 79% of the total, followed by the input sub-footprint with 12 %. [ABSTRACT FROM AUTHOR]

The province of Pinar del Río has very attractive landscapes, where forests play an important role in ecosystem services of scenic beauty and others. The forestry sector is in charge of their establishment, maintenance and conservation, whether they are plantations or natural forests. The fact of promoting in these sites of tourist interest, with the presence of forests in their landscapes, particularities of forest production and the actions of agroforestry enterprises, is an interesting potential for attraction and enjoyment. The scientific problem derived was, how to contribute to the national and international promotion of the most significant sites of forest production in Pinar del Río? The objective of this research consisted in proposing methodological elements for the design of a tourist route, which highlights the sites of interest with links to forestry production in Pinar del Río. To this end, a diagnosis was made in search of preferential sites, taking into account whether they were plantations or natural forests of different formations and management categories, logistically organizing how the route should be organized, taking into account different links of forest production (nurseries, different types of forests, harvesting, sawmills, among others); the regulations in force for this purpose were also considered, with a geographic information system with the possibility of information and updating. The preferred sites were Macurijes, La Palma, Minas de Matahambre and Guanahacabibes. According to the respondents, Macurijes was the most representative in terms of elements of the forest production chain and landscape attributes. [ABSTRACT FROM AUTHOR]

The study developed an empirical model for predicting the dominant height (H) and site index (SI) of Gmelina arborea Roxb. plantations considering biophysical and stand variables. Data from 160 stands located in the Andean, Caribbean and Pacific regions of Colombia were used. The Chapman-Richards model was selected for predicting H and SI of each stand. A correlation analysis identified the relative spacing, elevation and precipitation as variables related to SI. A multiple linear regression model with these variables explained 70 % of the total variation observed in SI. These variables included in the H model allowed to increase the fit index by 30 % and reduce the absolute error and mean square error by 40 and 41 %, respectively. The developed models are suitable for estimating productivity in areas with-out a history of forest plantations, adding flexibility and predictive capacity in a changing environment. [ABSTRACT FROM AUTHOR]

The site index is the main estimate for evaluating the productivity of a forest, as it makes it easy to classify stands according to their productive potential. The objective of the present work was to determine the productivity of Pinus pseudostrobus var. oaxacana through the guide curve method, by adjusting different forest growth models. The Michailoff model statistically presented the best fit. However, the Prodan model better represents the growth pattern of Pinus pseudostrobus var. oaxacana, although statistically the models are similar, showing high significance in the relationship between growth in height and age. [ABSTRACT FROM AUTHOR]

Areas with potential to establish Forest Germplasm Production Units (UPGF) with two varieties of P. pseudostrobus were determined. The objectives were (1) to model the current potential distribution of Pinus pseudostrobus var. pseudostrobus and P. pseudostrobus var. apulcensis using MaxEnt algorithms, and (2) to propose areas to locate the best individuals and establish UPGF in Michoacán and Oaxaca, Mexico. For these purposes, 2,451 data of presence obtained from own field records, Forest Biometric System, Global Biodiversity Information Facility and MEXU National Herbarium were used, as well as 19 predictor variables. The 75% of the records were used for training and 25% in validation. The adjustment and predictive capacity of ten models was evaluated; eight with 1,000 interactions and two with 500 were evaluated through precision tests of AUC (Area Under the Curve), ROC-standard (Receiver Operating Characteristics) and partial ROC. The models indicated that the two varieties present similar zones of potential distribution in a portion of the Neovolcanic Axis and Sierra Madre del Sur. The environmental variables with the most important contribution to the model for the pseudostrobus variety were those related to temperature; and for the apulcensis variety, temperature and precipitation. The establishment of UPGF can be carried out in areas of optimal growth; in addition, the data generated allow reducing the time and cost for the selection of the best individuals to be included in genetic improvement programs. [ABSTRACT FROM AUTHOR]

This article deals with forestry workers from the province of Misiones (northeast Argentina) who migrate to find temporary employment in other provinces. Our objective is to understand the link between spatial mobility and access to employment. Based on a qualitative methodology, we reconstruct the annual migratory cycles of workers, taking into account the variety of spatial paths and temporalities involved in migration and analyzing how these characteristics vary according to each worker's attributes, household strategies, and networks of access to employment. [ABSTRACT FROM AUTHOR]

Copyright of Revista Biológico Agropecuaria Tuxpan is the property of Revista Biologico Agropecuaria Tuxpan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Predicting the growth and yield of timber tree species is a prerequisite for planning sustainable forest management. The objective was to update several functions that integrate a compatible growth and yield system for Pinus patula, developed under the explicit wholestand model approach. System parameters were estimated using seemingly unrelated regression. For that, forest biometric information was used from four periodical inventories conducted in 42 permanent plots of 400 m2 in Hidalgo, Mexico. Almost all the functions of the system had good fit and satisfactory graphical behavior in their original structure. A polymorphic growth pattern explains stand productivity, which is interrelated with growth equations of basal area, mean diameter and total stem volume per hectare. The mortality function corresponds to an exponential model fitted under non-linear least squares method. The re-fitted system broadened the range of the growth equations to 31 years. The new system suggests a maximizing volume rotation of about 20 years for the average site. These results suggest that the commonly used 40 year rotation period used in the management plans in the region could be shortened if a proper density management strategy is applied. [ABSTRACT FROM AUTHOR]

Site quality estimation for forest production is normally accomplished by estimating height growth potential of forest stands, by developing equations that relate height and age of sample trees. However, there are places devoid of trees where investment in productive forests is feasible; better yet if quality potential of regenerating certain forest species can be estimated a priori. We have developed regressive mathematical models to estimate site index in natural stands of Pinus occidentalis, in major productive regions in the Dominican Republic, and established the relationship between index site and edaphic and physiographical variables. Developed models allow the assessment of the productive potential in places without trees. There were no significant differences (α = 0.05) between the site indexes averaged per plot in each locality, but a significant correlation was obtained among site index, height above sea level and aspect (0.273, P = 0.000 and 0.207, P = 0.003) respectively. There were also significant correlations between site index and soil organic matter content within the soil, sodium and potassium . The variables "height above sea level" and azimuth were statistically significant, and can be used to predict the productive potential of places where there are no trees within this region. The estimate of the productive potential by edaphic and physiographical variables for natural stands of P. occidentalis in productive areas constitutes an essential tool in the sustainable management of these forested areas. [ABSTRACT FROM AUTHOR]

It was developed a study about the influence of two types of micorrizogenos fungus in two types of different soils in forest species. It was on the nursery of Sempre, from de Integral Forest Company Guantánamo. The study took place from January to Mayo 2008 and 2009 in stonemasons of 20 m of long and 1 m of wide. The seeds of Swietenia mahagoni L. Jacq. (Caoba del país) and Lysiloma lastisiliquum Benth. (Soplillo) were seeding on bags of polyethylene in a brown carbonated and fluvisol soil with a proportion of 5:1 and 7:1 of soil bovine organic material. The design was completely randomized and six treatments were done applying 10g of arbuscular mycorrhizal of the Glomus hoi like and Glomus intraradices species below the seeds before the seeding. So, 20 plants of each treatment were evaluated and the growth of each of them was measured too. Besides, the diameter of the shoot the count of the number of leaves, wide of crown, the percent of mycorrhizal infection, the visual density and the mass of the arbuscular endophyte were also evaluated. The results evidenced a positive answer to the inoculation while some differences existed with the non inoculated witness. The combination of the Glomus intraradices + 7:1 with the best results in the brown soil was well observed. Meanwhile, the combination Glomus hoi like + 5:1 for the Fluvisol soid showed the best results. [ABSTRACT FROM AUTHOR]

Copyright of Spanish Journal of Rural Development is the property of Spanish Journal of Rural Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses the influence of forest engineer Octavio Elorrieta y Artaza on forest policy in Spain in the early 20th century. His career in the Spanish forest Administration is discussed, especially his proposals regarding forest resource utilization as a potential solution to agrarian social problems in southern Spain in the 1930s. The continuing relevance of his ideas about increasing forest resource productivity while conserving forestland is discussed, as are the shortcomings of his purely economic view of forestry.

An explicit growth and yield system (GYS) was fitted to data from re-measured plots of Cedrela odorata (spanish cedar) and Tabebuia donnell-smithii planted at the Oaxaca's coastal region. As a first stage, a total and merchantable volume system at tree level was fitted based on non-destructive sampling scheme. Afterwards a GYS was fitted using seemingly unrelated regression to achieve full compatibility among prediction and projection models. [ABSTRACT FROM AUTHOR]

The development of equations to predict yield and production of Pinus rudis Endl. is described. The data for model development were obtained from two measurements of a set of permanent plots located in Aloapan, Oaxaca. The prediction model is a whole stand model with a projection of diameter classes through the Weibull distribution. Stand's attributes are predicted with both, explicit and implicit predictions. The explicit prediction is based on modifications to the basal area and volume compatible growth models. The implicit prediction is made by recovering the diameter distribution predicted through the parameter prediction method. All growth models, even those related to the Weibull distribution parameter prediction showed an excellent fit. [ABSTRACT FROM AUTHOR]

The mangrove forest at Gandoca, Refugio Nacional de Vida Silvestre Gandoca-Manzanillo, Caribbean coast of Costa Rica, has been monitored since 1999, following the CARICOMP protocol. The dominant species was the red mangrove, Rhizophora mangle. The peak of productivity and flowering was in July. The mangrove productivity decline from 2001 to 2004 while the temperature rised. Biomass (14 kg/m²) and density (9 trees/10 m²) in Gandoca were relatively low compared to other CARICOMP sites, while productivity in July in Costa Rica (4 g/m²/day) was intermediate, similar to most CARICOMP sites. [ABSTRACT FROM AUTHOR]